Completed 25 June 1940.
Taken over by the Admiralty in February 1940.
Displacement: 580 tons.
Armament: 1 4" gun.

HMT St. Apollo (T/Lt Rupert Henry Marchington, RNVR) was sunk in a collision with the British destroyer HMS Sardonyx off north-west of the Isle of Lewis, Hebrides in position 59º13'N, 07º41'W. St. Appollo was spotted briefly by the starboard watch on Sardonyx, but missed by the Officer of the Watch. Sardonyx was heavily damaged foreward of the bridge, and reversed course back to Londonderry.